Various types of optical recorders are known in the prior art which are associated with digital data. These include computer output microfilm (COM) systems, laser printers, and electro-optical memories. In all of these prior art configurations, a digital signal is converted into an analog signal which controls the amplitude of a light beam. The light beam is directed at a radiation sensitive medium which records the signal applied thereto, thereby storing the information contained therein.
One closely related prior art electro-optical modulator array and recorder is described in U.S. Pat. No. 3,841,733, which discloses an optical waveguide system for producing a line of modulated radiation data for recording on a color film. U.S. Pat. No. 4,003,632 describes a similar structure which incorporates a floating gate as a charge storage structure. Such a floating gate is however associated in that patent with a semiconductor memory element, and information written into or read from such memory element by the light or propagating in the waveguide exciting or discharging the stored electronic charges. U.S. Pat. No. 4,094,606 describes a plurality of optical waveguides positioned between a common electrode and individual electrodes arrayed along a charged coupled device useful in a xerographic reproduction system.
Such prior art digital-to-analog optical recorders are not simple devices but rather are generally complex systems operating at relatively low speeds. Prior to the present invention there has not been a simple, high-speed and compact digital-to-analog data recorder which can be used in a wide variety of applications.